Railway-traffic-controlling apparatus



May 10 19.27.

R. M. GILSON RAILWAY TRAEFI C CONTROLLING APPARATUS Filed Feb. 17. 1926 I INVENTORZ Mr my:

patented May 16, E927.

unites star-es ATEN'l QF F'ICE.

ROBERT M. GILSON. OF PITTSBURGH. PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH 8c SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed February My invention relates to railway trafiic congoverning mean srcontrolled by current supplied to the rails of the section. One object of my invention is to prevent improper operation of the governing means for a section by stray current from an adjacent track section.

I will describe one form of railway trailic controlling apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a dia rammatic view illustrating one form of railway tratlic controlling apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the track rails of a stretch of railway track over which tratl'ic normally moves in the direction indicated by the arrow. These track rails are divided into a plurality of successive track sections A-B, B-C. etc. by short intermediate portions of track each designated by the reference character 1) with an exponent corresponding to the location and separated from the adjoining track sections by insulated joints in the track rails. For example, the short intermediate portion 1) dividing section A-B from section BC, is isolated from the rest of the track by means of two insulated joints 2 and 3" in rail 1 and two similar insulated joints 4: and 5 in rail 1.. lhe two rails of each intermediate portion 1) are connected to gether by a jumper 15.

Each track section is provided with a suitable source of alternating track circuit current here shown as a track transformer designated by the reference character '1 and having a secondary 8 connected across the rails adjacent the exit end of the associated section in series with an impedance 7. The primary 9 of each track transformer T is constantly supplied with alternating current from 17, 1926. Serial No. 88,799.

secondary 10 of an associated line transformer designated by the reference character L with an appropriate distinguishing exponent. Alternating current is constantly supplied to primary ll of each line transformer L from a suitable source of energy such as an alternator W over line wires it and 145*.

Each track section is also provided with a track relay designated in general by the reference character R with a suitable exponent and comprising two windings 12 and if one of which,12, is connected across the rails adjacent the entrance end of the section.

Associated with each track relay R'is a detector relay designated by the reference character G with an exponent corresponding to the location. Each of these detector relays is designed to be operated by uni-directional current and if supplied with alternating current requires an electromotive force across its terminals of many times the electromotive force required to operate the relay on uni-directional current. In apparatus embodying my invention, the detector relay is never supplied with alternating currrent of sufiicient electromotive force to operate the relay. and for purposes of the present disclosure it is therefore correct to state that the detector relays are responsive to unidirectional current but not to alternating current. Each detector relay G controls the supply of alternating current to winding 13 of the adjacent traclt relay as will be described hereinafter.

Connected in parallel with each insulated joint is an asymmetrical unit designated by the reference character 6 with a distinguishing exponent which unit is arranged to supply uni-directional current to the adjacent; detector relay. Each asymmetrical unit (5 may be of any suitable type such for example as the rectifier disclosed in an application for Letters Patent of the United States. Serial No. 1111. filed January 7, 1925, by Lars O. Grondahl, for unidirectional current carrying devices.

, or breaks down.

Referring particularly to detector relay G, this relay is provided with a circuit which may be traced from secondary 8 of track transformer T through wires l6 and i7, winding of relay G wire 18, rail. 1 of intermediate portion 1 jumper l5, rail 1 of intermediate'portion D, asymmetrical unit'G rail 1"of section AB and wire 19 back to secondary S of transformer T finder normal conditions, therefore, unidirectional-current is supplied to relay G from transformer T through the asymmetrical unit. (i The circuit for each of the remaining dctector rlays (9r :is similar to that just traced for relay G.

lVhen relay G is"clo sed';'* current "flows fron secondary 10 of transformer L, tlu ugh" wires'ill, and 23, front contact ofielay Gl, wire' 25, winding 13 of relay Rl WiresQ-G, 27 and 28, back 'to secondary IOof transformer L. hen this circuit ia'elose'd, alternating current is therefore supplied to winding 13 of relay R, and if, under these conditions alternating current alsosupplicd to winding ii of relay R, aswhen section BUis unoccupied, relay R will" be energized. ilhe' winding 13 of each of the remaining relays R is provided witha circuit similar to that just traced for winding 13 of relay R.

The track relays B may be used to control traffic gorerning means in any suitable manner. "In the form here shown each track section is prorided with a 'trackway signal iflesignated by the reference character S with an appropriate exponent and each capable of iiulicating procecd ;ir stop. lVhcn relay R is'energiz ed, current flows from secondary 10 of transformer L, through wires 21, 22 and 29, front contact 30 of relay R wire 31, operating mechanism of signal S, and wire's'32, 27 and 28, back to secondary 10 of transformer L \Vhen this circuit is closed signal S indicates proceed. \Vhen relayl} is deernugiaed, howerer. signal S indicates stop.

As shown in the drawing. section A- B and the section to the right of point C are unoccupied, and a train, indicated diagramiual'ically at occupies section i i-4". De-- tcctorrelays (x are all energized and alternating current is therefore supplied. to winding 13 of each track relay R. Current is also supplied to windings l2 of relays R and R, so that these relays are energized and signals 8 and S indicate proceed. lVinding 12 of relay R is shunted by the wheels and axles of train V so that relay B is de-energizciil and signal. S indicates stop.

Under some conditions it may happen that one or more of the insulated joints 2, 3, 4 In this event the track relay for one section may become improperly energized by stray current from an adjacent track section, even when the former section is occupied by a train. For example, I will assume that insulated joints 2 and 25 both break down. Current may then flow from secondary 8 of transformer 'l, through wire 19, rail 1 of section A'B insulated joint 2 rail ,1 of intermediate portion D insulated joint- 3 and rail 1 of section BC to winding 12 of relay R and thence from rail lof.section-B C, through the ground to rail 1 of section -P) and back to secondary Sj-of transformer T. The stray current thus supplied to winding .12 of relay R might be of sufficient magnitude to energize the relay.

' \Vith apparatus embodying my invention, however, a track relay can never become energized by straycurrent due to a broken down insulated joint. If insulated joint 2 breaks down asyn'nnetrical unit (i will be shunted and relay G will be supplied with alternating current from transformer T instead of with uni-directional current.- But 'the magnitude of thealternating*electromo supplied to winding 12 of the relay. Similarly, it should he noted that if insulated joint 3 should break down, the right-hand terminal of relay G would. be connected with rail 1. of section B C. As a resultof ZUU this connection, alternating currentwould flow from secondary 8 of transformer T through wire 19. rail 1 of section A-l. thence through the ground to rail. 1 of sec tion B-C, through the broken down insulated joint 3, rail 1 of intermediate portion D jumper l5. rail 1 of intern'iediate portion D, wire 18, winding of relay'tii and wire 17 back to secondary 8 of transformer T". The alternating currentthus supplied to relay G" would cause the relay to be de-energizc'd and the opening of front contact 24. would de-cnergize winding 12:) of relay R Similarly, should insulated joint. 5" break down, alternating current would flow from secondary 8 of transfm'imu- T, through wire 19 to rail 1 of section A.--B, thence through the ground to rail 1 of section B(. broken down joint 5, rail 1 of intermediate portion D wire 18, winding of relay (i and wire 17 back to secondary 8 of transformer T Alternating current supplied to relay (i over this leakage path would deenergize the relay as explained hereinbefore.

Furthermore, should insulated joint 4" break down. relay G would be connected directly across the impedance "7. The alterteases hat 'poteiiti'al drop at this impedance f outcifthen send an alternating current tliroiighthe winding of ielay'G and would cause the relay to open.

It wil l be observed from the foregoing that under no,.condi tion would a dangerouscondition arise, due to a broken down insulated joint.

If the leakage path through the ground which shunts asymmetrical unit (3 is of such high resistance that the relay G is not deenergized, an unsafe condition cannot result. because the leakage path will then also have too high a resistance to permit current of sufficient magnitude to leak from one section to the other to energize the track relay.

It should also be pointed out that the circuit for detector relay G is completely checked, for should any fault. occur in this circuit, the consequent de-energization of the detector relay would tie-energize the adjacent track relay.

Although I have herein shown and described only one form of railway traliic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

i. In combination, a stretch of railway track divided into two track sections by a short intermediate portion of track sepa rated from both said sections by insulated joints in the track rails, a source of alternating current connected with the rails of one said section. a track relay haying two windings one of which is connected with the rails of the other section, and means normally eti'cctive but rendered ineffective if any of said insulated joints break down for supply-dug alternating current to the remaining winding of said track relay.

2. In combination. a stretch of railway track divided into two track sections by a short intermediate portion of track separated from both said sections by insulated joints in the track rails, 21 source of alternating current connected with the rails of one said section. a track relay having two windings one of which is connected with the rails of the other section, a detector relay. means: normally cli'ective but rendered inclt'ective it any of said insulated joints break down for energizing said detector relay. and means controlled by said detector relay for supplying alternating current to the remaining winding of said track relay.

2). In combination, a stretch of railway track divided into two track sections by a. short intermediate portion of track separated trom both said sections by insulated joints in arc crack rails, source" o t alter: naan eu'rreat cohheet'ed wit'htheirails of one said section, 'a'traek 1'e1'ay -h'aving two windin s one "of which is connected Tw'ith the rail s of the o'tlr'e'r sectionia detector re l'ay,nieat1s net-m; ly e'fi'ectiv'e but; rendered inefi'ective it any of said insulated joints break down for energizing said detect-or relay, and a circuit for the remaining winding of said track relay including a source of alternating current and a front contact on said detector relay.

4. In combination, a stretch of railway track divided into two track sections by a short intermediate portion of track separated lrom both said sections by insulated joints in the track rails, a source of alternating current connected with the rails of one said section, a track relay having two windings one of which is connected with the rails of the other section, an asymmetrical unit connected across one of said insulated joints, a detector relay responsive to unidirectional current but not to alternating current, a circuit for said detector relay including a source of alternating current and said asymmetrical unit, and means controlled by said relay for supplying alternating current to the remaining winding of said track relay.

5. In combination, a stretch of railway track divided into a first and a second track section by a short intermediate portion of track separated from both said sections by insulated joints in the. track rails, a source of alternatii'ig current connected across the rails of said first section, a track relay having two windings one of which is connected across the rails of said second section, an asymmetrical unit connecting one rail of said intermediate portion with one rail of said first section. a jumper for connecting together the rails of said intermediate portion of track, a detector relay having one terminal connected with a rail of said intermediate portion of track and the other terminal connected with the remaining rail of said first section, and means controlled by said relay for supplying alternating current to the remaining winding of said track relay.

6. In combination. a stretch of railway track divided into a first and a second track section by a short intermediate port-ion of track separated from both said sections by insulated joints in the track rails, a source of alternating current connected across the rails of one said section, a track relay having two windings one of which is connected across the rails of the other section, an asymmetri al unit connected across one of said insulated joints, a detector relay responsive to uni-directional current but not to alternating current and connected with said source through said asymmetrical unit joints breaks down, and means controlled by seid detector relay for supplying alternating' currentte the remaining inding of said track relay.

, In testimony whereofI affix my signature.

ROBERT MGILSON. 

